Add ant task to check license and fix all files missing a licence

patch by David Capwell; reviewed by Jordan West for CASSANDRA-16198

build.xml

@@ -833,7 +833,7 @@
         depends="maven-ant-tasks-retrieve-build,build-project" description="Compile Cassandra classes"/>
     <target name="codecoverage" depends="jacoco-run,jacoco-report" description="Create code coverage report"/>
 
-    <target depends="init,gen-cql3-grammar,generate-cql-html"
+    <target depends="init,gen-cql3-grammar,generate-cql-html,rat-report"
             name="build-project">
         <echo message="${ant.project.name}: ${ant.file}"/>
         <!-- Order matters! -->
@@ -1214,6 +1214,24 @@
       </rat:report>
     </target>
 
+    <target name="rat-report" depends="rat-init" description="License checks on source" >
+      <rat:report xmlns:rat="antlib:org.apache.rat.anttasks"
+                  reportFile="${build.dir}/src.rat.txt">
+        <fileset dir="src/java"/>
+        <fileset dir="test/unit"/>
+        <fileset dir="test/distributed"/>
+      </rat:report>
+      <fail message="Some files have missing or incorrect license information. Check RAT report in ${build.dir}/src.rat.txt for more details!">
+        <condition>
+          <and>
+            <not>
+              <resourcecontains resource="${build.dir}/src.rat.txt" substring="0 Unknown Licenses" casesensitive="false" />
+            </not>
+          </and>
+        </condition>
+      </fail>
+    </target>
+
   <target name="build-test" depends="build" description="Compile test classes">
     <javac
      debug="true"
@@ -1665,6 +1683,8 @@
   <target name="rat-init" depends="maven-ant-tasks-init">
     <artifact:dependencies pathId="rat.classpath">
       <dependency groupId="org.apache.rat" artifactId="apache-rat-tasks" version="0.6" />
+      <remoteRepository refid="central"/>
+      <remoteRepository refid="apache"/>
     </artifact:dependencies>
     <typedef uri="antlib:org.apache.rat.anttasks" classpathref="rat.classpath"/>
   </target>

test/distributed/org/apache/cassandra/distributed/test/SimpleReadWritePathTest.java

@@ -1,3 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.apache.cassandra.distributed.test;
 
 import java.io.IOException;

test/distributed/org/apache/cassandra/distributed/test/ThriftClientTest.java

@@ -1,3 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.apache.cassandra.distributed.test;
 
 import java.io.IOException;

test/distributed/org/apache/cassandra/distributed/test/ThriftClientUtils.java

@@ -1,3 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.apache.cassandra.distributed.test;
 
 import java.net.InetSocketAddress;

test/unit/org/apache/cassandra/cql3/validation/operations/TTLTest.java

@@ -1,3 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.apache.cassandra.cql3.validation.operations;
 
 import java.io.File;